This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-041637, filed Feb. 18, 2000, the entire contents of which are incorporated herein by reference.
The present invention relates to a radio communication apparatus for performing authentication processing with the other apparatus via radio communication, and radio communication method.
In recent years, a wireless connection among radio communication apparatuses has been proposed by applying a communication method for performing data communication by constituting a radio communication network with a single parent apparatus and a plurality of child apparatuses, to the radio communication apparatus interface. In such communication method, usually, any radio communication apparatuses having a similar communication method can be connected each other, and the communication can be established with radio communication apparatuses within a distance range (for instance within a radius of 10 m) corresponding to their radio communication capability.
On the other hand, in case of an application to a personal computer and radio communication apparatuses functioning as its peripheral equipment, sometimes it is desirable to connect only to radio communication apparatuses within a limited range. For example, it is the case when a personal computer on one desktop is desired to be connected limitedly to peripheral equipment used by this computer, and not connected to remote computers or peripheral equipment used by the other.
By the way, for the initial connection for communicating by radio communication, an authentication processing is performed among radio communication apparatuses to communicate, in order to prevent a third party from intercepting communication data. In the authentication processing, inherent information (authentication information) is transmitted and received among radio communication apparatuses by radio communication, and once the other apparatus is authenticated by this authentication processing, thereafter, data communication is performed between both parties by a method for preventing communication contents from being leaked outside.
Thus, in the conventional communication method, the authentication information is transmitted and received among radio communication apparatuses in the authentication processing; however, if a radio communication apparatus to be connected and radio communication apparatuses not to be connected exist in the proximity area (radio electric wave range), the inherent information for authentication processing may be transmitted and received among theses both radio communication apparatuses. In other words, a nonspecific other party can intercept the authentication information, and the authentication processing may be performed simultaneously by an unintended radio communication apparatus.
Considering these problems, the Applicant has applied for a method for lowering output by the control section during the authentication processing, in Jpn. Pat. Appln. KOKAI Publication No. 11-96821, xe2x80x9cRadio communication apparatus, and its control methodxe2x80x9d. Namely, only a certain radio communication apparatus can receive the authentication information, by controlling the radio output during the authentication processing.
However, though the technology of the previous Application can prevent a nonspecific other from intercepting the authentication information, it requires an additional circuit such as control circuit for radio output control, and it should be improved in that it increases costs for the radio communication apparatus.
Consequently, it is an object of the present invention to provide a radio communication apparatus, and a radio communication method allowing to communicate by performing easily the authentication processing only with a specific other apparatus, without increasing the cost by adding a control circuit for radio output control or others.
According to a first aspect of the present invention, there is provided a radio communication apparatus for performing the authentication processing with other apparatus via radio communication, comprising:
an antenna detachably fitted to the apparatus;
detection means for detecting the detachment of the antenna; and
control means for performing the authentication processing upon the detection of detachment of the antenna by the detection means.
According to a second aspect of the present invention, there is provided a radio communication apparatus for performing the authentication processing with other apparatus via radio communication, comprising:
a radio communication antenna;
a communication circuit;
a switch for switching over connection and disconnection between the radio communication antenna and the communication circuit; and
control means for detecting the disconnection between the radio communication antenna and the communication circuit by the switch, and performing the authentication processing in connection with this disconnection.
According to a third aspect of the present invention, there is provided a radio communication apparatus for performing the authentication processing with another apparatus via radio communication, comprising:
a radio communication antenna;
a communication circuit;
a switch for switching over connection and disconnection between the radio communication antenna and the communication circuit;
detection means for detection connection or disconnection state between the radio communication antenna and the communication circuit by the switch at a predetermined timing; and
control means for performing the authentication processing upon the detection by the detection means of disconnection between the radio communication antenna and the communication circuit by the switch.
According to a fourth aspect of the present invention, there is provided a radio communication apparatus for performing the authentication processing with another apparatus via radio communication, comprising:
a switch for designating to perform the authentication processing;
output control means for lowering the radio communication output level to a predetermined value in connection with the operation of the switch; and
control means for performing the authentication processing, after the output level is lowered by the output control means.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.